Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dĕ-hisco, hīvi (in the inf. dehisse, v. the foll.), ĕre, v. n., to part, divide, go apart; to split open; to gape, to yawn (excepting once in Varr., not ante-Aug.): dehisse terram, Varr. L. L. 5, § 148 Müll.; so of the yawning earth, Verg. G. 1, 479; 3, 432; id. A. 4, 24 al.: unda dehiscens, id. ib. 1, 106: neque enim ante dehiscent Attonitae magna ora domus, id. ib. 6, 52: ex intervallo os paulum dehiscit, Cels. 7, 29 init.: cymba rimis, Ov. Tr. 5, 12, 27; cf.: navigium, springs aleak, Sen. Ep. 30: dehiscens intervallis acies, Liv. 29, 2: dehiscere ingentibus rimis, id. 91 Fragm. init.: rosa paullatim rubescens dehiscit ac sese pandit, Plin. 21, 4, 10, § 14; cf. ib. § 18 fin.: thynni pinguescunt in tantum ut dehiscant, burst open, id. 9, 15, 20, § 53.